hustcc / post-messenger

:baby: ~1 Kb wrapper of window.postMessage for cross-document communication.

post-messenger

A simple wrapper of window.postMessage for cross-document communication with each other.

一个简单的 window.postMessage 封装，用于跨文档的双向数据通信。

Feature

• Simple wrapper for postMessage.
• Use it just like event emitter.
• Event channel namespace supported.

Install

npm i --save post-messenger

or import it by script in HTML, then get PostMessenger on window.

<script src="https://unpkg.com/post-messenger/dist/post-messenger.min.js"></script>

Usage

• In parent document.

import PostMessenger from 'post-messenger';

// connect to iframe
const pm = PostMessenger('chat', window.iframe_name.contentWindow);

const listener = message => {
  console.log(message);
}

// listen the messages
pm.once('room1.*', listener);

pm.on('room1.user1', listener);

• In iframe document.

import PostMessenger from 'post-messenger';

// connect to parent
const pm = PostMessenger('chat', window.parent);

const listener = message => {
  console.log(message);
}

// send messages
pm.send('room1', 'All users of room1 will received.');

pm.send('*', 'broadcast message.');

Full example can be found here, and code here.

API

There is only one function named PostMessenger, you can get the instance by:

// projectId: the unique id of communication.
// targetDocument: the document which you want to connect and communicate.
const pm = PostMessenger(projectId, targetContentWindow);

The instance has 4 apis.

• pm.once(channel, listener)

Add a message listener on channel for once.

• pm.on(channel, listener)

Add a message listener on channel.

• pm.off([channel, listener])

Remove listener, if channel and listener are all undefined, remove all.

• pm.send(channel, message)

Send a message to the channel.

Scenes

The window.postMessage() method safely enables cross-origin communication between Window objects; e.g., between a page and a pop-up that it spawned, or between a page and an iframe embedded within it.

The communicate target can be:

• Window.open
• Window.opener
• HTMLIFrameElement.contentWindow
• Window.parent
• Window.frames

Reference here.

License

MIT@hustcc.

post-messenger's Issues

Bug of once & on

When once a function, and on a function.

Then trigger once function, the on function can not be trigger.

The target of Messenger is not necessary.

When just use post-messenger to listen message, the target of Messenger is not necessary.